A rotary refiner generally grinds pulp material, such as, for example, wood chips and clumps of larger fibers, into smaller fibers for use in the production of paper and paper-related products. In many cases, rotary refiners include two or more refining plates having opposable grinding surfaces. Typically, pulp is directed between the grinding surfaces of the refining plates and at least one of the refining plates is rotated relative to the other plate to grind the pulp between the rotary plates. This grinding action can also generate heat and exhaust vapor.